• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.218-218
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• 2011

낙동강은 4대강 살리기 사업에 의해 8개의 보(상주보, 낙단보, 칠곡보, 강정보, 달성보, 합천보, 함안보)가 하천 내에 건설되고 약 4억톤의 준설이 실시되면서 지형적으로 막대한 변화를 맞이하게 된다. 낙동강은 상류의 안동댐 및 임하댐에서 방류수, 중류의 구미 및 대구 등의 오염원 그리고 하류의 남강에 의한 영향 및 낙동강 하구언에 의한 정체에 의한 영향으로 지역적으로 수질 및 수리 특성이 서로 다르게 나타나고 있다. 낙동강에 건설되는 수중보들 또한 이러한 유입 및 경계 조건에 따라 서로 다른 수질특성을 나타낼 것으로 판단되며 이에 대한 영향을 미리 예측하고 발생 가능한 악영향에 대한 대안을 수립하는 것이 중요하다고 본다. 본 연구에서는 낙동강의 4대강 사업에 의한 지점별 및 시기적 영향을 정확하게 분석하기 위해 3차원 수리동역학 모델 EFDC와 수질모델 WASP을 연계하여 사용하였다. 연구대상지역은 안동댐 방류지점에서 낙동강 하구역까지의 총 334km의 지역을 포함하였으며 하천의 폭 방향, 수심방향 및 흐름방향에 대하여 3차원으로 격자를 구성하여 하천을 표현하였다. 수리 및 수질 보정에 필요 한 입력자료는 국토해양부 및 환경부 등에서 발표 된 자료를 이용하였으며 2007년을 기준으로 모의를 실시하였다. 4대강 살리기 사업에 의한 8개의 보 건설 및 낙동강 전역의 준설의 영향을 예측하여 사업 전 및 사업 후로 각각 구분하여 비교하였으며 사업 후 체류시간의 증가와 준설로 인한 수심증가에 따른 복합적인 원인에 의해 수질에 영향이 미치는 것으로 나타났다. 사업 후 낙동강의 각 수중보 출구 부근 지점에서 예측된 수질 특성은 사업전에 비하여 $BOD_5$는 전반적으로 감소하나, TN 및 TP 는 유사한 특성을 나타내었다. 그러나 Chl-a 농도는 상류와 중류에서는 체류시간의 증가로 증가하는 경향을 나타내었으며 이는 수질이 양호한 상류 지역에서 특히 큰 차이를 나타내는 경향으로 분석되었다. 그러나 낙동강 하구언 지역은 Chl-a 농도가 사업에 의해 약간 감소되는 경향을 나타내어 여타 구간과 다른 경향을 나타내었다. 이는 낙동강 하류의 Chl-a 농도가 이미 매우 높은 상태에서 체류시간에 의한 성장 촉진 보다는 수심증가로 인한 광량제한 효과가 더욱 지배적으로 나타난 것에 의한 영향으로 추정된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.211-217
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• 2010

This paper presents numerical investigations of the physical habitat changes induced by the hydropeaking in the downstream river of dam. For the two-dimensional ecohydraulic simulations, River2D model is used. Pirami (Zacco platypus) is selected as the target fish for investigating the impact of the hydropeaking. For validation of the model, the water surface elevations are simulated with two different water discharges. The computed results are compared with field data in the literature, and the result shows that the model successfully simulates the water flows. The weight usable area (WUA) of Pirami with the life cycle and the composite suitability index with different water discharges are computed and discussed. The results show that habitat for Pirami appears to be best in the bend region downstream of the dam. The discharge of the maximum WUA for adult Pirami is computed to be about 9 $m^3/s$. Also, the WUA computed in a condition of hydropeaking during seven days are presented. The averaged discharge of the hydropeaking appears to be about 20% larger than the drought flow, but the WUA by the hydropeaking is computed to be 60-100% smaller. This result shows that the hydropeaking reduces quantity of habitat available to fish.

• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1095-1106
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• 2008

Climate change and global warming are prevalent all over the world in this century and many researchers including hydrologists have studied on the climate change. This study also studied the impact of climate change on streamflows of a basin in Korea. The SWAT model was used to assess the impacts of potential future climate change on the streamflows of the Daecheong Dam Basin. Calibration and validation of SWAT were performed on a monthly basis for the year of 1982-1995 and 1996-2005, respectively. The impact of seven 15-year(1988-2002) scenarios were then analyzed for comparing it to the baseline scenario. Among them, scenario 1 was set to show the result of doubling $CO_2$, scenario 2-6 were set to show the results of temperature and precipitation change, and scenario 7 was set to show the result of the combination of climatologic components. A doubling of atmospheric $CO_2$ concentration is predicted to result in an maximum monthly flow increase of 11 percent. Non-linear impacts were predicted among precipitation change scenarios of -42, -17, 17, and 42 percent, which resulted in average annual flow changes in Daecheong Dam Basin of -55, -24, 25, and 64 percent. The changes in streamflow indicate that the Daecheong Dam Basin is very sensitive to potential future climate changes and that these changes could stimulate the increased period or severity of flood or drought events.

• Journal of Wetlands Research
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• v.24 no.1
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• pp.25-37
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• 2022

Climate change is becoming increasingly unpredictable. This has led to changes in various systems such as ecosystems, human life and hydrological cycles. In particular, the recent unpredictable climate change frequently causes extreme droughts and torrential rains, resulting in complex water resources disasters that cause water pollution due to inundation and retirement rather than primary disasters. SWAT was used as a watershed model to analyze future runoff and pollutant loads. The climate scenario analyzed the RCP4.5 climate scenario of the Meteorological Agency standard scenario (HadGEM3-RA) using the normal quantitative mapping method. Runoff and pollutant load analysis were performed by linkage simulation of climate scenario and watershed model. Finally, the results of application and verification of linkage model and analysis of future water quality change due to climate change were presented. In this study, we simulated climate change scenarios using artificial neural networks, analyzed changes in water temperature and turbidity, and compared the results of dams with artificial neural network results through W2 model, a reservoir water quality model. The results of this study suggest the possibility of applying the nonlinearity and simplicity of neural network model to Hapcheon dam water quality prediction using climate change.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.5
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• pp.17-23
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• 2011

Steel clapping plate is used to connecting rubber body in rubber dam. However, once the steel clapping plate corrodes, it may cause faults, such as the same problems experienced by typical reinforcing steel. This study evaluated the applicability of glass fiber reinforced polymer composite(GFRP) clapping plate as a substitute for steel clapping plate. Absorption and load test were conducted to evaluate the decrease in durability of GFRP clapping plate exposed to deterioration environments. In the durability test results, the absorption rate of GFRP clapping plate was appeared as 0.6~1.0% in 50 day of immersion time. Also, the fracture load decreased with accelerated degradation environment exposure. Moreover, the absorption rate in GFRP clapping plate increased as degradation progressed, reducing the fracture load.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.744-748
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• 2010

4대강 살리기 사업에 있어 하천 준설 및 다목적 보 설치는 주요하천 상 하류의 일괄적인 준설을 통한 통수단면 확보로 홍수 소통능력을 극대화 하고, 친환경적 보설치를 통해 하도정비 실시이후에도 현재의 갈수위 이상의 수위를 유지하면서 홍수피해저감효과를 극대화하는 것을 목표로 한다. 4대강 사업시 콘크리트 형식으로 건설될 다목적 보는 월류식 구조물이지만 보의 저부에서 발생하는 양압력이나 기타 재하 하중과의 조합으로 인해 전도나 활동을 일으킬 수 있는 가능성을 가질 수 있고, 보의 규모가 커지고 가동보 등의 복합적인 형태를 가질 경우 보의 붕괴는 콘크리트 중력식 댐의 붕괴와 비슷한 양상을 가질 것으로 판단된다. 본 연구에서는 월류 구조물이 붕괴되었을때 상 하류 하천에 미치는 영향을 분석하고자 하였다. 자연하천 내의 보 붕괴 및 그에 따른 수위상승으로 인한 제방 붕괴시 실제 범람원에 안정적으로 적용가능한 고정확도 2차원 홍수범람 모형을 평가하였고, 가상하도 및 실험하도에 대한 적용을 실시하였다.

• Restorative Dentistry and Endodontics
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• v.34 no.1
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• pp.38-41
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• 2009

When we use the total-etch dentin adhesive system for composite resin restorations, gel or liquid acid etchant such as 37% phosphoric acid is commonly used. Thirty seven percentage phosphoric acid is very powerful erosive agent, and can cause severe harmful effects when it contacts with an oral mucosa and facial skin. This case describes iatrogenic chemical burn on facial skin caused by phosphoric acid which was happened during composite resin restorative procedure. Chemical burn by acid etchant can be evoked by careless handling of remnant and syringe. In order to prevent these iatrogenic injuries, we should check the complete removal of the etching agent both in intra and extra-oral environments after etching and rinsing procedure and it is necessary to use of the rubber dam or isolation instruments. If accidental burn were occurred. immediate wash with copious water. And bring the patient to the dermatologist as soon as possible.

• Journal of the Korean association of regional geographers
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• v.10 no.2
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• pp.300-312
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• 2004

The geomorphological environment of Suwon Basin consists of two great elements: mountains which surround the basin and plains and low relief hills by differential erosion of granitic area. Nothern and eastern parts of the basin surround with gneissic mountains(Mt. Kwangkyo), southern and western parts of the basin with granitic mountains(Mt. Chilbo, etc). The basin developed on granitic saprolites is composed of two types of sub-order geomorphic elements: flood plains alongside four river(Whangkuji-chon, Seoho-chon, Suwon-chon, Wonchonri-chon) and aligned hills and mounts between the river side plains. While the low down lands provided the spatial condition for the extention of downtown of Suwon, the gneissic mountains have played the positive roles by high ecological dam effects with stable supply of water and purification of air, etc.

• Journal of Environmental Impact Assessment
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• v.25 no.1
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• pp.51-62
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• 2016

Recently, soil has been recognized as a crucially important resource that even can change the quality of life. Also, recent studies have gradually mentioned the importance of assessing soil impact induced by development plans and projects. In this study, after detailed soil assessement items were selected from our national environmental policies and international agreements, they were tested for the long-term dam construction planning in order to ensure more suitable implementation of strategic environment assessment(SEA). We found that soil resources can be impacted by diverse factors such as soil erosion, soil organic matters, soil moving, soil biodiversity, and others. Such detailed factors are found to be overlapped with the pervious EIA factors. Accordingly, additional studies would be required for finding out more reasonable connection between assessment factors during any SEA progress.

• Tunnel and Underground Space
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• v.18 no.5
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• pp.375-385
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• 2008

Hydraulic analysis in a dam that has a single outlet of water can be made through a simple comparison between the total precipitation and the volume of discharged water. In case of tailing dams this estimation could yield an error because several drainage facilities are worked independently as well as simultaneously. In this research, a capability of the drainage system in the tailing dam of the old Sangdong Mine was analysed by the means of GIS technic. As a result of this study, it was expected that in the normal working condition of the whole drainage system, the flooding of water over the dam should not occur in spite of the consecutive precipitation during one hour with an intensity of 80.31 mm/hr, a probable precipitation within 100 years. It was, however, revealed that, if the drainage system did not work completely, the water could flood over the dam when the total precipitation reached 251.1 mm.